Improvement in sheave-blocks



"llmitrdV tstr y @wat otitis.

THOMAS H.' RICE, OF BALTIMORE, MARYLAND. l

Letters Patent No. 106,507, dated August 16, 1870.

IMPROVEMENT IN SHEAVE-BLOCKS.

The Schedule referred to in these Letters Patent and making` part of the same.

To all yt'p'w'm rit may concern Be it known that I, THOMAS H. RICE,- of Baltimore, in the county of Baltimore and State of Maryland, have invented a new and improved Sheave- Block; and I do hereby declare 'the following to be a full, clear, and exact description of the same, reference being had to the accompanying drawing making apart of this specilicatioIn-in which- Figure 1 is a diagonal vertical section through the block, and L Figure 2 is an elevation ot' the inner surface of' one side of the block, showing t-he friction-rollers.

This invention consists of frictionrollers mounted in boxes, which are placed in both the inner sides of a pulley-block, in such manner that the rollers project inward beyond the surfaces -of thesides, so as to prevent the sheave from coming in contact with the block and wearing the same away. In the drawingl I a. care the side pieces of a wooden sheave-block.

b b, Ithe end pieces that are interposed between the side pieces, and fastened to the same by bolts.`

c, the sheave placed iu the space iucloseda between the side and end pieces..

ll, the shaft on which thesheave rotates.

e e'are metal boxes let Hush into the inner surfaces of the side pieces et.Y

f are friction-rollers mounted in said boxes, and projecting beyond the inner surfaces of the side pieces u., so as to prevent the sheave from eating into the same as it rotates. In pulley-blocks destitute of any such provision, the sheave rapidly eats a recess in one or both sides of the block, and thusrenders the latter useless. My arrangement prevents all such Wear, and greatly contributes to the preservation of the block.

- Having thus described my invention,

What I 'claim as new, and desire to secure by Letters Patent, is-

The blockal b, boxes e, and rollers jQ/all4 arranged as spemhed' THOMAS. e. mon.

Y XVitnesses:

THORNTON ROLLI'NS,

WILLIAM 'l RICE. 

